I suspect Mathematica 5 was the culprit of two nasty Windows XP
crashes I have experienced during the past four months. In the second
one, Internet Explorer (which was running when Mathematica's kernel
crashed) got hopelessly corrupted. I'm not 100% sure it's Mathematica,
but it is my prime suspect. Even if it is Mathematica, I'm ready to
forgive it because it is such a great piece of software otherwise.
However, it would it interesting to know when Mathematica is known to
crash and what can be done to avoid destabilizing Windows (which is
NOT a great piece of software). After the second crash, my rule is
this: don't run anything else when Mathematica is working.